The dual role of a bHLH protein: Is SCRM1 / ICE1 an integrator of cold-stress and stomatal fate signaling?

bHLH 蛋白的双重作用：SCRM1 / ICE1 是冷应激和气孔命运信号的整合者吗？

• 批准号: 179169260
• 负责人: Dr. Robin Jonathan Horst
• 金额: --
• 依托单位: Department of Biology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/179169260?language=en
• 关键词: dual; role; bHLH; protein; SCRM1

The formation of functional cell patterns in multicellular organisms requires specific cell-fate determinants. The outcome of this formation is influenced by the environment. Stomatal development in the plant Arabidopsis thaliana provides an easily accessible model to study the integration of environmental cues into developmental processes. Stomata are valves in the plant epidermis that regulate the gas exchange between the air and the intercellular spaces. The number of stomata per leaf area is influenced by CO2 and light intensity, and systemic signaling is thought to be involved in controlling stomatal development in response to these cues. Two basic helix-loop-helix (bHLH) transcription factors (TFs), SCRM1 and 2, play a key role in regulating the entry of protodermal cells into the stomatal lineage and in the progression through the stomatal lineage that ultimately forms mature stomata. SCRM1 interacts with three known bHLH TFs (SPCH, MUTE and FAMA) that positively regulate sequential steps during stomatal cell-state progression, but regulators of SCRM-activity in the stomatal lineage are unknown. The epidermis of dominant scrm-D mutants develops only stomata, so scrm-D provides a basis for a genetic screen for SCRM regulators. The finding that SCRM1 is ICE1, a regulator of freezing tolerance, suggests a dual role of SCRM1, which may act as an integrator of abiotic stress signaling and stomatal development. This project aims at unraveling the molecular mechanisms that regulate both functions of SCRM1 and at understanding the impact of cold signaling on stomatal development. It will give insight into how environmental cues are integrated into developmental processes. Three specific aims are: 1: Determine the role of systemic cold signaling in stomatal development. 2: Unravel mechanisms that regulate SCRM1 or ICE1 action on the post-translational level. 3: Identify novel factors that regulate the dual function of SCRM1.

在多细胞生物中，功能性细胞模式的形成需要特定的细胞命运决定因素。这种形成的结果受环境的影响。拟南芥（Arabidopsis thaliana）的气孔发育为研究环境因素与发育过程的整合提供了一个简单的模型。气孔是植物表皮上的阀门，调节空气和细胞间隙之间的气体交换。每叶面积气孔数受CO2和光强的影响，系统信号被认为参与控制气孔发育以响应这些信号。两个基本螺旋-环-螺旋（bHLH）转录因子（TFs） SCRM1和scrm2在调节原真皮细胞进入气孔谱系和通过气孔谱系最终形成成熟气孔的过程中发挥关键作用。SCRM1与三种已知的bHLH TFs （SPCH， MUTE和FAMA）相互作用，积极调节气孔细胞状态进展过程中的顺序步骤，但气孔谱系中SCRM1活性的调节因子尚不清楚。显性SCRM - d突变体的表皮只发育气孔，因此SCRM - d为筛选SCRM调控因子提供了基础。研究发现SCRM1是ICE1，是一种抗冻性调节因子，这表明SCRM1具有双重作用，可能是非生物胁迫信号和气孔发育的整合者。该项目旨在揭示调节SCRM1功能的分子机制，并了解冷信号对气孔发育的影响。它将深入了解环境因素是如何整合到发展过程中的。三个具体目标是：1 .确定系统冷信号在气孔发育中的作用。2：阐明在翻译后水平调控SCRM1或ICE1作用的机制。3：发现调控SCRM1双重功能的新因子。